Method for manufacturing a mesa type semiconductor device and mesa type semiconductor device

摘要

PROBLEM TO BE SOLVED: To provide a manufacturing method of a mesa type semiconductor device which prevents characteristics from being deteriorated by generating a deep level over a whole region of a semiconductor substrate.SOLUTION: The manufacturing method of the mesa type semiconductor device includes: a semiconductor substrate preparation step of preparing a semiconductor substrate 110 including an ntype silicon substrate 112, an ntype epitaxial layer 114 and a ptype anode layer 116; a groove forming step of forming a groove 126 for mesa region formation having depth exceeding at least pn junction from a surface of the ptype anode layer 116; a heavy metal containing paste layer forming step of forming a heavy metal containing paste layer 118 on an inner face of the groove 126; and a heavy metal diffusion step of forming a heavy metal diffusion region 122 by diffusing a heavy metal into the semiconductor substrate 110 by heating the inside of the semiconductor substrate 110 by irradiating the inside of the semiconductor substrate 110 with laser light L1 from the surface of the groove 126 at a predetermined inclination angle and over a full circumference of the groove 126.